diff --git a/src/libcore/extfmt.rs b/src/libcore/extfmt.rs
index 3f58548684c..534f2a492d2 100644
--- a/src/libcore/extfmt.rs
+++ b/src/libcore/extfmt.rs
@@ -164,28 +164,26 @@ mod ct {
         let noflags: [flag] = [];
         if i >= lim { ret {flags: noflags, next: i}; }
 
-        // FIXME: This recursion generates illegal instructions if the return
-        // value isn't boxed. Only started happening after the ivec conversion
         fn more_(f: flag, s: str, i: uint, lim: uint) ->
-           @{flags: [flag], next: uint} {
+           {flags: [flag], next: uint} {
             let next = parse_flags(s, i + 1u, lim);
             let rest = next.flags;
             let j = next.next;
             let curr: [flag] = [f];
-            ret @{flags: curr + rest, next: j};
+            ret {flags: curr + rest, next: j};
         }
         let more = bind more_(_, s, i, lim);
         let f = s[i];
         ret if f == '-' as u8 {
-                *more(flag_left_justify)
+                more(flag_left_justify)
             } else if f == '0' as u8 {
-                *more(flag_left_zero_pad)
+                more(flag_left_zero_pad)
             } else if f == ' ' as u8 {
-                *more(flag_space_for_sign)
+                more(flag_space_for_sign)
             } else if f == '+' as u8 {
-                *more(flag_sign_always)
+                more(flag_sign_always)
             } else if f == '#' as u8 {
-                *more(flag_alternate)
+                more(flag_alternate)
             } else { {flags: noflags, next: i} };
     }
     fn parse_count(s: str, i: uint, lim: uint) -> {count: count, next: uint} {
diff --git a/src/libcore/str.rs b/src/libcore/str.rs
index 618fa04a314..c7c037c4238 100644
--- a/src/libcore/str.rs
+++ b/src/libcore/str.rs
@@ -665,8 +665,6 @@ Returns:
 The original string with all occurances of `from` replaced with `to`
 */
 fn replace(s: str, from: str, to: str) : is_not_empty(from) -> str unsafe {
-    // FIXME (694): Shouldn't have to check this
-    check (is_not_empty(from));
     if byte_len(s) == 0u {
         ret "";
     } else if starts_with(s, from) {
diff --git a/src/libcore/sys.rs b/src/libcore/sys.rs
index 40b50c1ad4b..9d9bdb58078 100644
--- a/src/libcore/sys.rs
+++ b/src/libcore/sys.rs
@@ -73,12 +73,6 @@ fn refcount<T>(t: @T) -> uint {
     ret rustrt::refcount::<T>(t);
 }
 
-// FIXME: There's a wrapper for this in the task module and this really
-// just belongs there
-fn unsupervise() -> () {
-    ret rustrt::unsupervise();
-}
-
 fn log_str<T>(t: T) -> str {
     rustrt::shape_log_str(get_type_desc::<T>(), t)
 }
diff --git a/src/libcore/task.rs b/src/libcore/task.rs
index 0b8abdc36a7..ec6f98fbf45 100644
--- a/src/libcore/task.rs
+++ b/src/libcore/task.rs
@@ -72,6 +72,7 @@ native mod rustrt {
     fn start_task(id: task, closure: *rust_closure);
 
     fn rust_task_is_unwinding(rt: *rust_task) -> bool;
+    fn unsupervise();
 }
 
 /* Section: Types */
@@ -287,10 +288,7 @@ fn join(task_port: joinable_task) -> task_result {
         if _id == id {
             ret res
         } else {
-            // FIXME: uncomment this when extfmt is moved to core
-            // in a snapshot.
-            // fail #fmt["join received id %d, expected %d", _id, id]
-            fail;
+            fail #fmt["join received id %d, expected %d", _id, id]
         }
       }
     }
@@ -303,7 +301,9 @@ Detaches this task from its parent in the task tree
 
 An unsupervised task will not propagate its failure up the task tree
 */
-fn unsupervise() { ret sys::unsupervise(); }
+fn unsupervise() {
+    rustrt::unsupervise();
+}
 
 /*
 Function: currently_unwinding()